A basic truck scale configuration uses four load cells and a single platform, which is generally 25′ long×12′ wide. However, the platform size and number of load cells used can vary widely depending on the application. For example, two or more basic scales can be set end to end or side by side to build a longer or wider scale, a section of foundation could be built between the two scales, or a spacer platform could be hung between two scales. Furthermore, truck scales can be installed in a variety of different ways such as above ground, inside a deep pit, inside a shallow pit, or in some combination such as a three-sided pit.
Designing a scale for the weighing of heavy vehicles, such as cargo carrying trucks, presents a number of unique problems. For example, a conventional truck scale is normally an outdoor installation which is exposed not only to the elements, but also to chemicals, such as road salts, oil, transmission fluid, brake fluid, antifreeze, diesel, gasoline, and so on. Some scales are even subject to more extreme elements such as garbage, coal, and aggregate. For instance, scales used in garbage dumps are often subject to over filled trucks, which spill their contents onto the platform of the scale. The spilled garbage then finds its way into the pit below the platform along with other fluids leaked from the truck. This necessitates not only the scale being robust in order to withstand these elements, but also the removal of the platform for cleaning and/or servicing.
Another unique scale design problem is that once a scale is installed it must be calibrated in order to provide accurate readings. A calibrated scale must precisely maintain its configuration as established at the time of calibration in order to provide accurate and repeatable measurements. This calibration can be lost if even one of the load cells is shifted out of position by more than a minute amount. This generally means that a scale must be realigned and recalibrated each time the platform is removed, which is a time consuming and costly activity.
In order to avoid the need for realignment and recalibration, the platform must be placed precisely where it was at the time it was initially calibrated.
What is desired, therefore, is a truck scale with a removable platform that does not require to be realigned and recalibrated each time the platform is removed.